1. Technical Field of the Invention
This invention relates to a fluid compressor, and more particularly to a method for assembling a motor driven fluid compressor having the compression and drive mechanisms within a hermetically sealed container.
2. Description of the Prior Art
Motor driven fluid compressors having the compression and drive mechanisms within a hermetically sealed housing are known in the art. For example, Japanese Patent Application Publication No. 2-275085 discloses a compressor including a hermetically sealed housing which contains a compression mechanism, such as a scroll type fluid compression mechanism and a drive mechanism therein. The housing includes a cylindrical portion, and a first and second cup-shaped portions. An opening end of the cylindrical portion is hermetically connected to one opening end of the cylindrical portion by, for example, brazing. An opening end of the second cup-shaped portion is hermetically connected to another opening end of the cylindrical portion by, for example, brazing.
The scroll type fluid compression mechanism includes a fixed scroll having a first circular end plate and a first spiral element which extends from one end surface of the first circular end plate. An inner block is fixedly disposed within one opening end region of the cylindrical portion by, for example, forcible insertion and is fixedly connected to the first circular end plate of the fixed scroll by a plurality of bolts. The scroll type fluid compression mechanism further includes an orbiting scroll having a second circular end plate and a second spiral element which extends from one end surface of the second circular end plate. The orbiting scroll is disposed within a hollow space which is defined by the inner block and the fixed scroll. The first spiral element of the fixed scroll interfits with the second spiral element of the orbiting scroll with an angular and radial offset. The first circular end plate of the fixed scroll is radially slidably disposed on one end surface of the inner block.
A drive mechanism includes a drive shaft and a motor surrounding the drive shaft. The drive shaft includes a pin member which extends from and is integral with one end of the drive shaft. The axis of the pin member is radially offset from the axis of the drive shaft, and the pin member is operatively connected to the second circular end plate of the orbiting scroll.
A rotation preventing mechanism is disposed between the inner block and the second circular end plate of the orbiting scroll so that the orbiting scroll only orbits during rotation of the drive shaft. The inner block includes a central bore through which the drive shaft passes. A bearing is fixedly disposed within one opening end portion of the central bore so as to rotatably support one end portion of the drive shaft.
The motor includes an annular-shaped rotor fixedly surrounding an exterior surface of another end portion of the drive shaft and an annular-shaped stator surrounding the rotor with a radial air gap. The stator of the motor is fixedly disposed within a middle region of the cylindrical portion by, for example, forcible insertion.
According to the above-mentioned construction of the compressor, all of the internal component parts are assembled within only the cylindrical portion of the compressor housing in an assembling process of the compressor. In a final step of the assembling process, the first and second cup-shaped portions are hermetically connected to one and another opening ends of the cylindrical portion respectively so that the assembling process of the compressors is completed.
Accordingly, in the final step of the assembling process, the weight of the assembled cylindrical portion takes an extremely high percentage of the total weight of the compressor. Therefore, the assembled cylindrical portion is handled with difficulty when the assembled cylindrical portion is required to be transported or to change its position during the final step of the assembling process.
Furthermore, according to the above-mentioned construction of the compressor, the compressor must be assembled along only one assembly line. Therefore, even when a part of the assembly line gets out of order, the whole of the assembly line does not work so that the assembly line can not be flexibly managed.